广西普通野生稻白叶枯病广谱抗源的鉴定与评价

Identification and evaluation of Guangxi wild rice (Oryza rufipogon Griff) resources with wide spectrum resistance to bacterial blight

[目的]鉴定与评价1498份广西普通野生稻对白叶枯病的抗性,为培育广谱持久的白叶枯病抗性水稻品种提供材料.[方法]利用华南籼稻区优势菌株（Ⅳ型）,对1498份广西普通野生稻进行抗性初筛鉴定;并根据初筛获得的部分抗性稳定材料进行多菌系重复鉴定;对广西普通野生稻的居群抗病性与遗传多样性进行相关分析.[结果]经抗性初筛,获得70份对白叶枯病抗性稳定的材料;利用7个广西优势菌株（广西Ⅰ～Ⅶ型菌株）对其中60份材料进行广谱抗性筛选鉴定,结果发现在60份材料中,对Ⅰ～Ⅶ菌株抗性表现中抗以上的材料分别为43、50、45、58、52、46和46份.两份材料（RB11和RB19）对7个供试菌株均表现为抗水平;3份材料（RB5、RB7和RB31）分别对Ⅶ、Ⅴ、Ⅴ型菌株表现高抗.相关性分析结果表明,广西普通野生稻抗性材料出现的频率与居群遗传多样性指数相关性不显著,但与居群地理纬度呈极显著负相关.[结论]鉴定获得一批广谱抗源和高抗野生稻材料,可作为今后水稻白叶枯病抗性育种的重要抗源亲本.

[Objective]The resistance of 1498 accessions of Guangxi wild rice （Oryza rufipogon Griff） to bacterial blight （BB） was evaluated in order to provide materials for breeding rice varieties with wide spectrum of resistance to BB. [ Method]The dominant type Ⅳ strain in indica rice planting regions of South China was used for identifying 1498 accessions of Guangxi wild rice. The resistances of selected accessions were further identified by using several other BB races. In addition, the correlation between disease resistance of Guangxi wild rice population groups and their ge- netic diversity was also analyzed. [Result]By using type IV strain, 70 accessions wild rice with stable resistance to BB were obtained. Through further identification of 60 accessions with 7 dominant strains of Guangxi （ Ⅰ - Ⅶtype strain）, 43, 50, 45, 58, 52, 46 and 46 accessions were found to be moderate resistant, resistant, or high resistant to Ⅰ - Ⅵ/ type strain, respectively. Two accessions, viz., RB11 and RB19, were resistant to all 7 tested strains. Three ac- cessions, viz., RB5, RB7 and RB31, presented high resistance to the Ⅶ, V and Vtype strain, respectively. The re- sistant material frequency of Guangxi wild rice was not significantly correlated with genetic diversity index of popula- tion group, but negatively correlated with the geographic latitude of O. rufipogon population groups. [Conclusion] Some wild rice accessions with wide spectrum resistance and high resistance to BB were obtained through resistance i- dentification, and they could be used for BB resistant parents on breeding rice varieties.